//#include "Head.h"
//struct TreeNode {
//    int val;
//    struct TreeNode* left;
//    struct TreeNode* right;
//};
//int countNodes(struct TreeNode* root)
//{
//    if (root == NULL)
//    {
//        return 0;
//    }
//
//    return countNodes(root->left) + countNodes(root->right) + 1;
//}
//
